1. Technical Field
The present disclosure relates to orthopedic surgical devices, and more particularly, to a spinal implant and a method of use.
2. Discussion of Related Art
The spinal column is a complex system of bones and connective tissues that provide support for the human body and protection for the spinal cord and nerves. The adult spine is comprised of an upper and lower portion. The upper portion contains twenty-four discrete bones, which are subdivided into three areas including seven cervical vertebrae, twelve thoracic vertebrae and five lumbar vertebrae. The lower portion is comprised of the sacral and coccygeal bones. The cylindrical shaped bones, called vertebral bodies, progressively increase in size from the upper portion downwards to the lower portion.
An intervertebral disc along with two posterior facet joints cushion and dampen the various translational and rotational forces exerted upon the spinal column. The intervertebral disc is a spacer located between two vertebral bodies. The facets provide stability to the posterior portion of adjacent vertebrae. The spinal cord is housed in the canal of the vertebral bodies. It is protected posteriorly by the lamina. The lamina is a curved surface with three main protrusions. Two transverse processes extend laterally from the lamina, while the spinous process extends caudally and posteriorly. The vertebral bodies and lamina are connected by a bone bridge called the pedicle.
The spine is a flexible structure capable of a large range of motion. There are various disorders, diseases and types of injury, which restrict the range of motion of the spine or interfere with important elements of the nervous system. The problems include, but are not limited to, scoliosis, kyphosis, excessive lordosis, spondylolisthesis, slipped or ruptured discs, degenerative disc disease, vertebral body fracture, and tumors. Persons suffering from any of the above conditions may experience extreme or debilitating pain and diminished nerve function. These conditions and their treatments can be further complicated if the patient is suffering from osteoporosis, or bone tissue thinning and loss of bone density.
Spinal discs between the endplates of adjacent vertebrae in a spinal column of the human body provide critical support. However, due to injury, degradation, disease or the like, these discs can rupture, degenerate, and/or protrude to such a degree that the intervertebral space between adjacent vertebrae collapses as the disc loses at least a part of its support function. This can cause impingement of the nerve roots and severe pain.
In some cases, surgical correction may be required. Some surgical corrections include the removal of the natural spinal disc from between the adjacent vertebrae. In order to preserve the intervertebral disc space for proper spinal column function, an interbody spacer can be inserted between the adjacent vertebrae.
Typically, a prosthetic implant is inserted between the adjacent vertebrae and may include pathways that permit bone growth between the adjacent vertebrae until they are fused together. However, there exists a possibility that conventional prosthetic implants may not provide a fusion due to various conditions and factors, including the fact that the implant does not allow optimal space for bone ingrowth and the implant does not mimic bone density sufficiently to allow for the creation of bone growth factors. In these cases the body rejects the implant and a non-union (no fusion) occurs. When there is a non-union, the implants may be dislodged or moved from their desired implanted location due to movement by the patient or insufficient bone ingrowth.
Therefore, a need exists for a spinal implant that can mimic the density of bone and allow for optimal bone ingrowth and provide a solid fusion of the vertebral segments. In addition, it is desired that an implant be utilized to prevent expulsion of the interbody device by utilizing a spinal plate.